Airplane running light



June 128 1938- F. c. BRECKENRIDGE 2,121,783

AIRPLANE RUNNING LIGHT Filed Feb. 5, 19:57

i INQENTR BYf-'m/vc/s C. BREcKE/vR/DGE /gfu/V a ATTORNEY VPatented June '2.8, 1938 PATIENT `oFFlCls:ffff

` MRPLANERUNNING LIGHT ...Francis-AC. reckenrdge, Washington, 1).-0.Y y Applicationrebruay 3, 1937, serial No, 123,873 Y il z'claims. i (c1. '24o-r1.7) (Granted the act` of Marchl 3, 1883,y as

f Y amended April30, 1928; 3'70` O. G. 75'7)V easily kassembled when necessary rfor replacement of the light bulb.

A further object of this invention `is to provide an airplane running'A light unit having such aerodynamic qualities as to keep at a mi-nimum any drag or interference with the aerodynamic qualities of the airplane wing to which it is applied.

A still further object of this invention isto pro-` vide V.a running lightv streamlined shield which kalso acts to hold the light dome anchored inf!-` position.

with the above and other' objects in view, mev

` invention consists inthe construction, combination and arrangement 'of parts as will be hereinafter more fully described." Y Y Reference is to be had to the accompanying drawing forming apart` of vthis specification in which like reference characters indicate correwhich: Y

' Fig. 1 is a top plan'view of theairplane run- :ning light unit Yof this invention;

` Fig. Y2 is ka sectional view on line 2--2; fand drawing. Y Y Y There is shownY at lil a running light lamp mounted in a socket I I through which extend suitable conduits to the lamp contacts I2. Extending o 'upwardly from the socket Il is the reflectorY I3 g provided with suitablereector surfaces so as to `insure that the light will be reflected at the most appropriate angle. Yical surface at vI4 having its center of curvature substantially at the center of the lamp filament and extending from the cylindrical neck I6 to a plane passing substantially through said filament center. Atltherear is a second spherical surface I5 havingits center of curvature substantially Vin the plane 20 and forward of the lamp filament. The surface at. I1 is a toroidal surface generated by a circular', parabolic, or other appropriate arc rotatedabout an axis lin its own plane,

said axispassing through thecenter of curvature 55 spending parts through theA several views, and in Y Fig. 3 is a sectional View on line 3-3 of the The reflector I3 has a spherof the surfaceA I5. Ingeneral the surfacel I1 is vtangent rto `the `surface I5 and extends fromther Vplane of such tangency to a plane I9 passing substantially-through-the center of the lamp -la- Y Vv:ment and making adihedral angle of 110e, or

other rper'scribed' value, with the y 1 u plane 2 0, which,v limitsrt-he spherical surface lI 5. The surface *I4 is connected to the surfaces I'5 and |11 by connecting surfaces of whatever configuration may `be found convenient. The neck of the reflector I6 extends through a hollow recess in a protuberance'ZI in the head of the unit base 22. K

This unit base 22 is shaped substantially as shown, being provided vwith screw head receiving apertures 23 and 24 through which screws may be placedfor securing the entire unit in proper l position on the airplane wing. A depending boss 25 is'provided so as to makeplace for a threaded aperture 23 into which may extend'a screw 21, fromvthe shield 28. It will be observed that theV base 22 isprovided with an undercut groove 29 against which the edges of the shield 28are held by the screw 21, it being-further, observed that a flare 30 around the rear edges and sides'of the streamlined outer surface of theshield 28. 'Ihe base 22 is alsogprovided about the hollow recess in theprotuberance 2I with a cylindrical recess 3l, ending in a rabbet 32. A bulb and reflector covering dome 33, preferably made of suitably colored glass or other transparent material, is u provided with a cylindrical rabbet 34 adapted to .f t'into the .cylindrical recess 3| andv have the edge 35 Vabut against the rabbet 32 on the unit base22. VThe upper end 36 of the shield28 rests f over the top of the dome 33 as shown, and lserves to hold it rmly in position, the single screw 21 thus serving to hold both'the dome 33 and the shield 28 in assembled position. The assembled running light unit as thus provided, is substantially'tear-drop orstreamlined in shape,A as will be apparent from Fig. 1, the spherical dome 33 providing the head of the teary drop, lwhile the shield 2B and flare 3l) provideV the'streamlined tail, thuskeeping aerodynamic resistance thereof at a minimum. It will be fur- Vther observed that the front edge 38 `of the unit base 22 merges smoothlyupward into the outer surface or dome 33. In assembling the unit on an airplane wing or tail surface, it vis intended i that the protuberance 2 I, lamp base and connecting conduit all be countersunk'in the airplane unit base 22 provides a smooth continuationof the wing or tailsurface below the base line 31 of the Vention, and that various changes in constructhe general and preferred embodiment of my intion, proportion and arrangement of parts may be made within the scope of the appended claims` longitudinal Cross-section of a tear drop, a lampV l receiving protuberance extending downwardly through the head of said base, a semi-spherical dome, intertting rabbets on said dome and said protuberance, and means for quickly and detachably securing said dome to said base with said Y dome and protuberance rabbets in cooperating relation, said securing means comprising an undercut groove extending about the tail of the base and a shield having one end bearing in said undercut groove andthe other end bearing on said dome to the rear of its high point and a single member extending through said shield intermediate said Vbearing points and secured to said base.

2. An aircraft running light comprising a'base Whose outline is substantially that dened by aV longitudinal cross-section of a tear drop, a lamp receiving protuberance extending downwardly through the head of said base, a semi-spherical dome, intertting rabbets on said dome and said protuberance, and means for quickly and detachably securing said dome to said base with said dome and protuberancerabbets in cooperating relation, 'said securing means comprising an undercut groove extendingabout the tail of the base and a shield having one end bearing in said undercut groove .and the other end bearing on said dome tothe rear of vits high point and a,V single member extending through said shield intermediate said bearing points and secured to saidl base, said member Vcomprising a screw having its head countersunk in said shield and threaded into said base, said shield merging smoothly vitl'r said'dome and with said base to provide a stream- .lined surface of 'minimum aerodynamic resist- Y FRANCIS C. BRECKENRIDGE. 

